agent_participation_ceiling_widen· reason_code· applies to state_resolutionSub-reason for failed_precondition when a Realm/Circle/Strand agent_participation ceiling write would widen (enable a bit disabled by) its parent ceiling. The deployment ⊇ Realm ⊇ Circle ⊇ Strand ceiling chain is tighten-only (monotone). See zh/models/realm-and-space.md, zh/models/circle.md, zh/authz/capabilities.md §5.4.